• Journal of the Semiconductor & Display Technology
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• v.13 no.1
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• pp.109-112
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• 2014

H.264/AVC is an international video coding standard that is established in cooperation with ITU-T VCEG and ISO/IEC MPEG, which shows improved code and efficiency than the previous video standards. Motion estimation using various macroblock from 44 to 1616 among the compression techniques of H.264/AVC contributes much to high compression efficiency. Generally, in the case of small motion vector or low complexity about P slice is decided $P16{\times}16$ mode encoding method. But according to circumstances, macroblock is decided $P16{\times}16$ mode despite large motion vector. If the motion vector variance is more than threshold and final select mode is $P16{\times}16$ mode, it is switched to $P8{\times}8$ mode, so this paper shows that the storage capacity is reduced. The results of experiment show that the proposed algorithm increases the compression efficiency of the H.264/AVC algorithm to 0.4%, even reducing the time and without increasing complexity.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.4
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• pp.237-243
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• 2019

A high-efficiency and small-sized switched-mode line transformer (SMLT) is proposed in this study. The conventional structure of an adapter is composed of line transformer and rectifiers. This structure has a limit in miniaturizing due to low-frequency line transformer. Another structure is composed of power factor correction (PFC) and DC/DC converter. This structure has a limit in reducing volume due to two-stage structure. As the proposed SMLT is composed of an LLC resonant converter, a high-frequency transformer can be adopted to achieve isolation standards and size reduction. This proposed structure has different operation modes in accordance with line input voltage to overcome poor line regulation. In addition, the proposed SMLT is applied to the front of a conventional PFC converter, because the SMLT output voltage is restored to rectified sinusoidal wave by using a full-bridge rectifier in the secondary side. The design of the PFC converter is easy, because the SMLT output voltage is controlled as rectified sinusoidal wave. The validity of the proposed converter is proven through a 350 W prototype.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.5
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• pp.41-51
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• 2022

The research looks into the impact of stock split announcements on stock prices and market efficiency in the Colombo Stock Exchange (CSE). This research uses a sample of 26 stock split announcements that occurred between 2020 and June 2021. According to the Global Industry Classification Standards, the stock split announcements covered in the study pertain to 26 businesses and 9 industries (GICS). To obtain the results, the usual event research methodology is used. The findings demonstrate significant average abnormal returns of 15.01 percent on the day the stock split news is made public and abnormal returns of 4.11 percent and -4.05 percent one day before and after the stock split announcement date, respectively. The study's findings revealed significant positive abnormal returns one day before the disclosure date, indicating information leakage, and significant negative abnormal returns the next day after the announcement date, indicating CSE informational efficiency. Because stock prices adapt so quickly to public information, these findings support the semi-strong form efficient market hypothesis, which states that investors cannot gain an abnormal return by trading in stocks on the day of the stock split announcement.

• Journal of Korean Society of Archives and Records Management
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• v.12 no.1
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• pp.189-207
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• 2012

It is necessary to diagnose the standard record management system when the system is being spread out to entire public organization and institutions. This study aims to analyze the standard record management system for improving system and revising the related standards in the future. This study evaluates the satisfaction on the interface and functional quality of the system through questionnaire survey on records managers. It is found that the satisfaction of functional quality is just above the line, but the interface fails to satisfy records managers. Also the reliability of the system appears to be higher satisfaction than efficiency and usability. Therefore, the study suggests that the standard records management systems should try to improve 'easy of use' and effectiveness and efficiency by implementing heavy batch job and promoting modulation of key function. And the study emphasizes that the standards will be revised with the long-term plan in order to develop standard records management system systematically and continuously.

• Journal of Cadastre & Land InformatiX
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• v.47 no.2
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• pp.213-231
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• 2017

The development of new spatial technologies enables sustainability as well as the efficiency of future land management while maintaining the efficiency of current land management. In this context, what are the challenges facing land management and sustainability, how can set the relationship between the land management and sustainability? What is sustainable technology for land management? And how can sustainability challenges and technologies be applied to land management? and so on. Therefore, this study is to search sustainable land management direction by investigating and applying sustainable technologies for more efficient and continuous maintenance of land management. To describe and approach sustainable technologies for land management, in particular, capacity, security, IT resource, new device, standards, transparency, and data, access to data and so on that can be considered as the challenges of sustainability and land management.

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.113-126
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• 2017

PURPOSES : This study proposes standards for rural access road pavement section and thickness design considering existing access road construction conditions; the study also proposes a complementary policy that can be used for design convenience. METHODS : Various literature review and case studies had been performed in terms of rural access road section and thickness design, both domestically and internationally, and this was followed by domestic rural access road field surveys. KPRP and KENLAYER were used to analyze the commonalities and predict the remaining life. Data on real cost is used to select an appropriate construction method through economic analysis. RESULTS : The economic efficiency of concrete pavement ($15{\times}15$) was the highest in terms of economic efficiency of performance life and traffic volume. In the case of asphalt pavement, it is considered that the most economical method is to implement micro-surfacing method four times as a preventive maintenance method (once every 10 years and 4.5 years for asphalt concrete pavement and MS construction method, respectively). Repairable asphalt pavement is advantageous for areas where heavy vehicles are expected to pass. In the case of other general areas, it is considered economical to place concrete ($15{\times}15$) pavement. However, as analytical results on its performance life are unavailable, it is to be considered for study in the future. CONCLUSIONS : This study proposed interim design guidelines based on various domestic and international design guidelines and case studies. However, in order to develop the final design criteria applicable to the field, it is necessary to (a) estimate the bearing capacity of the lower level of the pavement at various sites, (b) estimate the daily traffic volume, (c) implement advanced low-cost pavement technologies, and (d) propose maintenance standards and techniques for long-term performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2446-2452
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• 2012

In order to meet the recently enhanced emission standards at home and abroad, it is necessary to develop the CRDI ECU control algorithm that users can adjust fuel injection timing and amount in response to their needs. Therefore, this study developed the simulator for knocking analysis that enables knocking discrimination and engine balance correction applicable to the ECU exclusive to the industrial CRDI engine. The purpose of this study is to provide the driver-oriented diagnostic service that enable drivers to diagnose vehicles directly by developing diagnostic devices for vehicles with ths use of the results of the developed simulator for knocing analysis according to the OBD-II standards. For this purpose, this study aims to improve the fuel efficiency of vehicles by proposing the S/W design method of the OBD-II diagnosis device that can provide real-time communcations with the use of wired system and bluetooth module as a wireless system to send and recevice automobile fault diagnosis signal and sensor output signal, and to suggest an improvement for engine efficiency by minimizing the generation of harmful exhaust gas.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.6
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• pp.73-82
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• 2005

This study was performed to evaluate the need for heating wastewater to enhance treatment efficiency of organic matter (BOD, SS) during cold winter in newly developed Absorbent Biofilter System (ABS) which was established in the Suwon Campus of the Seoul National University. Treatments consisted of non-heating (2000 year) and heating(2001, 2002 year), and sampled data were analyzed during cold winter period as well as post winter period to investigate the influence of heating after winter season. Even the average air temperature showed only $0.4^{\circ}C$ difference between two experimental years, the difference in the average effluent temperature during cold winter period between heating and non-heating experiment was approximately $11^{\circ}C$. The average effluent concentration of organic matter in non-heating treatment exceeded the Korean standards for water quality of discharged effluent in riparian area (BOD and SS 10 mg/L); however, the standards were met in case of heating treatment during both winter and post winter period. Therefore, the need fur heating wastewater during cold winter season in ABS was justified. On the other hand, there was no improvement of treatment efficiency in T-N and T-p, but we observed the more activated nitrification as increasing the wastewater temperature. Because the average underground temperature was $5^{\circ}C$ higher than the average air temperature during cold winter period, we recommend that the ABS can be established in the underground rather than on-ground for saving the heating cost.

• Clean Technology
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• v.2 no.2
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• pp.51-59
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• 1996

Billions of tons of industrial waste are generated annually in industrialized countries. Managing and legally disposing of these wastes costs tens to hundreds of billions of dollars each year, and these costs have been increasing rapidly. The escalation is likely to continue as emission standards become even more stringent around the world. In the face of these rapidly rising costs and rapidly increasing performance standards, traditional end-of-pipe approaches to waste management have become less attractive. The most economical waste management alternatives in many cases have become recycling of the waste or the redesign of chemical processes and products so that wastes are prevented or put to productive use. These strategies of recycling or reducing waste at the source have collectively come to be known as pollution prevention. The engineering challenges associated with pollution prevention are substantial. This presentation will categorize the challenges in three levels. At the most macroscopic level, the flow of materials in our industrial economy, from natural resource extraction to consumer product disposal, can be redesigned. Currently, most of our raw materials are virgin natural resources that are used once, then discarded. Studies in what has come to be called industrial ecology examine the material efficiency of large-scale industrial systems and attempt to improve that efficiency. A second level of engineering challenges is found at the scale of individual industrial facilities, where chemical processes and products can be redesigned so that waste is reduced. Finally, on a molecular level, chemical synthesis pathways, combustion reaction pathways, and other material fabrication procedures can be redesigned to reduce emissions of pollution and unwanted by-products. All of these design activities, shown in Figure 1, have the potential to prevent pollution. All involve the tools of engineering, and in particular, chemical engineering.

• Journal of Energy Engineering
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• v.28 no.3
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• pp.34-41
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• 2019

It is essential to introduce EERS (Energy Efficiency Resource Standards) according to the trend of the era in which energy saving is emphasized, and it is time to settle down in a stable manner. Electric motors and lighting devices, which account for more than 60% of the nation's electricity use, are the most effective items of the EERS. And accurate methods of calculating savings must be preceded. In this study, the operation rate and load rate are measured through the demonstration of energy use at 400 businesses and the measured rates are used for EERS savings calculation. The results imply that the proposed method can be successfully applied to calculate cost-effective and reliable energy savings.